Organogel-Emulsions with Mixtures of β-Sitosterol and γ-Oryzanol: Influence of Water Activity and Type of Oil Phase on Gelling Capability
Organogel-Emulsions with Mixtures of β-Sitosterol and γ-Oryzanol: Influence of Water Activity and Type of Oil Phase on Gelling Capability
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DOI：
10.1021/jf300313f
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发表时间：
2012-04-04
影响因子：
6.1
通讯作者：
van der Linden, Erik
中科院分区：
文献类型：
--
作者：
Sawalha, Hassan;den Adel, Ruud;van der Linden, Erik
在这项研究中，油包水乳剂是由含有不同盐浓度的水分散在含有β-谷甾醇和γ-谷维素混合物的油相中制备的。在纯油中，β-谷甾醇和伽马-谷维素分子自组装成管状微结构，产生牢固的有机凝胶。然而，在乳状液中，水分子与β-谷甾醇分子结合，形成一水晶体，阻碍小管的形成，导致较弱的乳胶体。在水相中加入盐会降低水的活度，从而抑制谷甾醇一水晶体的形成，即使在延长储存时间(约1年)后也是如此。当乳液中的极性油含量较低时，乳液的管状微结构得到改善，从而显著提高了乳液凝胶的硬度。本研究的主要结论是，降低水分活度和/或使用低极性油可以促进谷维素和谷甾醇管状微结构的形成。
In this study, water-in-oil emulsions were prepared from water containing different salt concentrations dispersed in an oil phase containing a mixture of beta-sitosterol and gamma-oryzanol. In pure oil, the beta-sitosterol and gamma-oryzanol molecules self-assemble into tubular microstructures to produce a firm organogel. However, in the emulsion, the water molecules bind to the beta-sitosterol molecules, forming monohydrate crystals that hinder the formation of the tubules and resulting in a weaker emulsion-gel. Addition of salt to the water phase decreases the water activity, thereby suppressing the formation of sitosterol monohydrate crystals even after prolonged storage times (similar to 1 year). When the emulsions were prepared with less polar oils, the tubular microstructure was promoted, which significantly increased the firmness of the emulsion-gel. The main conclusion of this study is that the formation of oryzanol and sitosterol tubular microstructure in the emulsion can be promoted by reducing the water activity and/or by using oils of low polarity.